1. Field of the Invention
This invention relates generally to accessories for toy or model railroad layouts and more particularly to an improved combination signal and train detector for such layouts.
There is a demand for model railroad accessories that simulate signals used on full sized railroads. Such accessories include block signals, semaphores, wig-wag signals and others. A block signal controls the passage of trains by providing a red or green signal to the engineer indicating whether it is safe to pass the block signal.
In full size trains, signals such as block signals semaphores and the like (collectively referred to herein for convenience as block signals) are controlled by a variety of complex mechanisms the precise duplication of which is not practical in model train layouts. This invention may be applied to signals that control the passage of trains, and to signals that control the passage of vehicular traffic at grade crossings. Accordingly, it has become common to provide block signals in model train layouts that turn red when a train approaches and turn green after the train has passed. Previously known block signals have been relatively simple devices that include a red light and a green light that can be selectively illuminated by applying appropriate activating signals to inputs of the block signal. The inputs to the block signals have come from a variety of sources generally referred to as train detectors. Known train detectors include detectors that use a section of isolated track that is responsive to a train passing over it and light or magnetic sensors to detect the presence of a passing train.
2. Background Art
Heretofore, providing block signals responsive to the passage of trains has required the use of multiple devices and sometimes complex wiring connections between them.
It is an object of this invention to provide a combination of a block signal and train detector that greatly simplifies installation compared with known approaches.
It is another object if this invention to provide a combination block signal and train detector that can be easily synchronized with similar devices positioned at remote locations on a model train layout.
It is another object of the invention to provide a combination block signal and train detector that uses simple inexpensive circuitry that allows the device to be manufactured and sold at reasonable prices